Building with Steel , Need some sizing advice

[meledward23]

Well,

I am going to put together a greenhouse. I plan to build the thing out of steel. I figure several coats of an oil based pait should protect it enough that it won't rust out until after a) I am dead or b) I have moved.

But I need some advice from someone that works with steel a little more than I and or my family.

The structure is going to be 20' long, 10' wide, 8' tall at the house, and 6' tall on the outside edge (lean-to). I do plan on having a 12" or 18" Blockfoundation/ perimeter for the structure to sit on.

The polycarbonate paneling that will cover the frame is sold in 4' or 6' widths. Since I am going 20' wide I figure 4' widths makes sense. The panels themselves only weigh .266 pounds per square foot.


So here is where I am headed. I have to select a material to make the corner posts, door frame, header (one on house, one opposite wall). Finally Crossmembers on the roof and wall studs.

So any advice on what to use, (preferabbly from someone who similar structures out of steel). 2x2 Angle 1/4" thick, Square Tubing? , Channel? Oh and of course spacing across the roof.

Of course if anyone knows where a good steel load chart is that would help. My Father has the expertise to do all the calculations one could want (he has more hours of collegiate mathematics than I have undergraduate hours with a degree). But sometimes real world experience is a little more helpful.

Welding is not an issue, plenty of experience in that market available (Brother).

Oh did I mention I am budget concious, (hence not aluminum).

Thanks,

Matthew

 

[RonR]

I can't help you with the structural details; the stuff I build I eye ball and follow the advice of a buddy "Anything worth building is worth OVERBUILDING". Hence, my stuff is usually plenty stout.

And I base what I'm building on what I can buy at the surplus iron store--that saves some bucks.

My concern would be getting some GOOD paint on that steel. A greenhouse will be a terrrible wet environment--RUST will love it. If you build it so it can be bolted together (much harder), you could get it powdercoated to make it last. If not, I'd use some of the new stuff that turns rust to _________ and prevents it. Then topcoat it.

You will NOT want to have to repait the steel once it is up.

Ron

 

[JimR]

There are a few places on the NET to look. Here's one I found.
Steel web page

 

[meledward23]

As far as painting it, you think something different than rustoleum is needed ?

I figure a good high quality oil based, several layers after I have it framed out was my ovjective.

Honestly the only steel work I have done is with my brother, Trailers, Cars, 3PH implements, and some 6" Square tubing to support his garage when he cut the trusses out for his lift.

 

[Egon]

I beleive you can buy load bearing galvanized metal studs.

Egon

 

[JimR]

Rustoleum should work fine for that. Do you know any engineers? They have books that can give you the info you need.

 

[dmccarty]

Matthew,

Have you though of using PT lumber instead of steel. That might be easier and you sure would not have to worry about rust.

Sigh. I had some links booked marked regarding greenhouses. Key word HAD. I had found some companies that sold the green house "glass" and frames to hold it when used as a roof. It seemed like a good system. Not sure if you have thought about the roof yet so I figured I would mention their are people selling roofing systems. Sure wish I had the site....

If I find it I'll shout out.

Later,
Dan